Nowadays there are trends to reuse architectures and technical solutions developed for different kinds of telecom networks, such as fixed broadband access networks and mobile access networks (or, more generally, Third Generation Partnership Project (3GPP) networks). This is generally known as Fixed and Mobile Convergence (FMC). Service providers are pushing for the so called FMC solutions in order to optimize their network costs and increase end user experience. In respect to FMC, two standardization organizations—3GPP and BroadBand Forum (BBF)—have started a collaboration task in order to define the required architecture for FMC. Efforts are being made in 3GPP and BBF to devise solutions that allow the technical advantages provided by any of these two network domains—i.e., the broadband fixed network domain as defined by, e.g., the BroadBand Forum, BBF, and the mobile network domain as defined, e.g., by the 3GPP—to be available to user terminals (referred generally as User Equipments or UEs), regardless of whether a UE connects to a telecom network in a wired or wireless access manner.
FIG. 1 shows an exemplary FMC (BBF-3GPP) interworking architecture 10 depicted in 3GPP Technical Specification (TS) 23.139, version 1.0.0 (August 2011), titled “3GPP System-Fixed Broadband Access Network Interworking; Stage 2” (hereafter, “TS 23.139”). In the present discussion, portions of this TS 23.139 related to policy and QoS interworking are incorporated by reference in their entireties. As is known, the TS 23.139 specifies the Stage 2 system description for interworking between a 3GPP system 12 and a Fixed Broadband Access network 14 defined by BBF to provide the Internet Protocol (IP) connectivity to a 3GPP UE (e.g., the UE 16 in FIG. 1) using a Wireless Local Area Network (WLAN) (such as, for example, a WiFi network) (not shown) and a Home Evolved Node-B (HeNB) or Home Node B (HNB) (not shown) connected to the Fixed Broadband Access network 14. The fixed network 14 and the mobile network 12 may be owned and/or operated by different service providers/operators or the same service provider/operator. In the discussion herein, terms like “Fixed Broadband Access network,” “broadband fixed network domain,” Broad Band Fixed network domain,” and other such terms of similar import are used interchangeably to refer to a BBF defined access and network such as, for example, the network 14 in FIG. 1. Similarly, in the discussion herein, terms like “3GPP network,” “3GPP mobile network domain,” “mobile network domain,” “mobile access network,” and other such terms of similar import are used interchangeably to refer to a wireless network based on, for example, 3GPP specifications such as a 3GPP Evolved Packet Core (EPC) based system like the 3GPP Evolved Packet System (EPS) 12 shown in FIG. 1. For the sake of brevity, only a brief discussion of various elements in FIG. 1 is provided herein, while focusing in more detail on those elements that are particularly relevant to the present invention.
The upper part in FIG. 1 represents nodes in a mobile network domain 12 (referred also herein as “3GPP domain”, for the sake of illustrating a preferred embodiment disclosed with respect to network arrangements disclosed by 3GPP specifications with respect to mobile networks) that comprises a 3GPP EPS 12 having a 3GPP EPC as mentioned before. The term “EPC” may generally refer to a set of Core Network (CN) nodes of an EPS domain of a 3GPP network, but excluding radio access network nodes such as GSM/Edge Radio Access Network (GERAN) nodes (wherein “GSM” refers to “Global System for Mobile Communications”), Universal Terrestrial Radio Access Network (UTRAN) nodes, Evolved UTRAN (E-UTRAN) nodes, WLAN nodes or other similar radio access network nodes. In particular, the upper part in FIG. 1 illustrates some nodes of the 3GPP EPC such as, for example, a Packet Data Network Gateway (PDN-Gw) 18, a Serving Gateway 20, and a Policy and Charging Rules Function (PCRF) 22. The Serving Gateway 20 may be coupled to the PDN-Gw 18 through an S5 reference point and to the PCRF 22 via a Gxc reference point. The PCRF 22 may be coupled to the PDN-Gw 18 via a Gx interface as shown. It is noted here that the terms “reference point” and “interface” are used interchangeably herein as can be understood from the context of discussion. In FIG. 1, the 3GPP EPS 12 is shown to also include a 3GPP access network 24, which may include, for example, the Evolved Universal Terrestrial Radio Access (EUTRA) or E-UTRAN air interface for the 3GPP Long Term Evolution (LTE) network. The access network 24 may be coupled to a Home Subscriber Server (HSS) 26 via an S6a reference point. As is understood, the HSS 26 may maintain subscription-related information (e.g., subscriber profiles) for users “homed” (as opposed to “roaming”) in the service provider's EPS 12 and may also provide support with user authentication and user's service authorization status. In that regard, the HSS 26 may be coupled to a 3GPP Authentication Authorization and Accounting (AAA) server 28 via an Swx reference point. The 3GPP AAA server 28 may be coupled to the PDN-Gw 18 via an S6b reference point as shown. The 3GPP mobile network domain 12 may also include a service network 30 to provide network operator's additional IP-based services (e.g., mobile broadband or multimedia content delivery services) to users/subscribers. Such services may include, for example, the IP Multimedia Sub-system (IMS) based services, Packet-switched Streaming Service (PSS), etc. The service network 30 may be coupled to the PCRF 22 via an Rx interface and to the PDN-Gw 18 via an SGi interface as shown.
The lower part in FIG. 1 represents nodes of a Fixed Broad Band network 14, which is also referred to herein as “broadband fixed network domain” (also abbreviated as “BBF domain.”). In FIG. 1, the “partition” between the 3GPP and BBF domains is represented by dotted line 31 for ease of reference. Like the 3GPP AAA server 28 in the 3GPP domain 12, the BBF domain 14 may also include a BBF AAA proxy server 32 for user authentication, authorization, and accounting functions in the BBF domain. Both of these servers 28, 32 may be coupled to each other via an STa reference point. Additionally, the BBF domain 14 may include a Broadband Network Gateway (BNG) (or Broadband Remote Access Server (BRAS)) 34 functioning as an IP Edge Router where bandwidth and QoS policies may be applied. A Broadband Policy Control Function (BPCF) 36 may be coupled to the BNG 34 to provide a Policy Decision Point (PDP) (discussed below in more detail) in the fixed network domain 14. The BPCF 36 may be coupled to its counterpart PDP in the 3GPP domain—i.e., the PCRF 22—via an S9a reference point (which is discussed in more detail below). The interconnections among the BNG 34, the BPCF 36, and the BBF AAA proxy server 32 may be as shown. Additionally, the BNG 34 may be coupled to the PDN-Gw 18 in the 3GPP domain as well. As explained in 3GPP Technical Report (TR) 23.852, in a trusted environment, the BNG 34 may be coupled to the PDN-Gw 18 via an S2a reference point, which implies a GPRS Tunnel Protocol (GTP) tunnel from BNG to PDN-Gw (wherein “GPRS” stands for “General Packet Radio Service”). In FIG. 1, the BBF domain 14 is shown to include an Access Node (AN) 38 coupled to the BNG 34. The AN 38 may implement one or more access technologies based on different communication media such as, for example, copper, fiber, or wireless. The AN 38 may include, for example, a Digital Subscriber Line Access Multiplexer (DSLAM) to provide Ethernet-based access (via copper or fiber lines) to BBF domain 14, or an Optical Network Terminal (ONT) that can convert fiber optic light signals into copper (electric) signals for processing in the BBF domain 14.
As shown in FIG. 1, the AN 38 may receive its traffic (e.g., voice calls, Internet data, multimedia content including audio and video, etc.) from a customer premises network 40, which may include a residential or corporate network (e.g., Ethernet-based, Asynchronous Transfer Mode (ATM)-based, etc.) supporting broadband access via a Residential Gateway (RG) 42 coupled to the AN 38. The customer network 40 may include one or more BBF devices 44 (e.g., a phone, a laptop computer, etc.) coupled to the RG 42 (e.g., via a wireline Ethernet connection such as, for example, a Digital Subscriber Line (DSL) cable) and configured for broadband access. Similarly, a user (i.e., a user device such as an Internet-enabled phone or computer) in the customer premises network 40 may be wirelessly connected to the RG 42 via a WiFi Access Point (AP) 45 (e.g., a wireless router), which itself may be connected to the RG 42 via a wireline connection (e.g., through a DSL modem or via an Ethernet cable). In this manner, a user in the customer network 40 may access broadband services offered through the BBF domain 14.
In FIG. 1, the dotted line 47 represents UE's 16 access to the 3GPP mobile network domain 12 using a 3GPP access (not shown), whereas the straight line 48 represents UE's connection to the mobile network domain via a WiFi network (represented by the WiFi AP 45) at the customer premises network 40. FIG. 1 specifically illustrates non-roaming FMC architecture for trusted Fixed Broadband Access network based on S2c. The S2c reference point for the connections 47-48 provides a communication channel between the terminal/UE and the PDN-Gw 18 in the mobile domain. Thus, as shown in the non-roaming scenario in FIG. 1, the UE 16 can connect to the mobile domain 12 either directly through a 3GPP access (as represented by the dotted line 47) or via the fixed broadband network 14 (as represented by the solid line 48), which, in turn, can be accessed through a customer premises network 40. The UE 16 may have been configured to process (i.e., receive and transmit) broadband multimedia content (e.g., Internet data, voice calls, audio-visual content, Voice-over-IP (VoIP), or any other multimedia content) offered through various operator-specific services (e.g., Push-to-talk over Cellular (PoC) service, an online gaming platform, UE's location-dependent content delivery service, etc.) in the 3GPP domain 12 and the BBF domain 14.
It is noted here that although FIG. 1 is related to a non-roaming situation (for the sake of simplicity), the present discussion (and invention) applies to a roaming FMC architecture as well (examples of such roaming architectures are shown in 3GPP TS 23.139). It is further noted that although there may be additional nodes/components in each of the networks 12, 14, 40 shown in FIG. 1, these additional architectural details are not shown in FIG. 1 for the sake of clarity and due to their lack of relevance to the present discussion. It is also observed that because TS 23.139 (from which FIG. 1 is taken) relates to 3GPP implementations, details of interconnections (e.g., type of interface/reference point) between BBF nodes/elements and also between nodes or units in the customer premises network are not provided in the architectural diagram shown in FIG. 1. Such details are not relevant here, but may be obtained from fixed network based BBF protocols, technical reports, or other technical literature, if needed.
For FMC purpose, 3GPP has defined a Work Item called BroadBand Access Interworking (BBAI), which is divided into three Building Blocks (BB). BB1 defines the architecture (an example of which is shown in FIG. 1) that enables a user terminal (or UE) to access services offered by the mobile operator using both fixed access and mobile access via gateways known in the 3GPP terminology as Packet Data Network Gateways (PDN-Gw). This is a pure interworking scenario, in which there are two separated networks—mobile (according to 3GPP EPC network architecture) 12 and fixed (according to BBF architecture) 14. The existence of two separated networks 12, 14 implies that the fixed network 14 and the mobile network 12 may belong to different operators or to the same operator, but there are two policy nodes that, as Policy Decision Points (PDP), can intervene in any case for making policy decisions with regard to a UE's data communications—a BPCF (e.g., the BPCF 36 in FIG. 1) as a PDP for the fixed network 14, and a PCRF (e.g., the PCRF 22) as a PDP for the mobile network 12.
Thus, although policy management solutions addressing policies for access control, Quality of Service (QoS) control and enforcement, and charging, have been deployed for both kinds of network domains (i.e., fixed and mobile network domains), with regard to QoS control and enforcement, these solutions comprise, essentially, two types of nodes: (1) PDPs implemented by nodes (e.g., BPCF 36 and PCRF 22) acting as policy servers (in respective domains) and deciding the policies (QoS policies) with regard to a UE's data communication, and (2) Policy Enforcing Points (PEP) commonly implemented by nodes routing data packets of data communications and communicating with PDPs to put into force the policies decided by these PDPs with respect to the data communications the PDPs process. In the fixed domain 14, the BNG 34 may function as a PEP, whereas in the mobile domain 12 a Bearer Binding and Event Reporting Function (BBERF) (not shown) may function as a PEP under the Policy and Charging Control (PCC) architecture for a 3GPP core network as disclosed in 3GPP TS 23.203, version 11.3.0 (September 2011), titled “Policy and Charging Control Architecture” (hereafter “TS 23.203”), the disclosure of which is incorporated herein by reference in its entirety.
As noted above, with regard to policies (e.g., QoS policies) to be decided in respect to a data communication of a user terminal (or UE), the currently envisaged FMC solutions comprise the use of two PDPs—a first one (i.e., the BPCF 36) in the broad band fixed domain 14 and a second one (i.e., the PCRF 22) in the 3GPP mobile domain 12. As shown in FIG. 1, these two PDPs communicate through an interface named as “S9a” (or as “S9*” in other specifications). The interface “S9a” envisaged for FMC is inspired in the functionality of the “S9” interface disclosed in 3GPP TS 23.203 mentioned above. The “S9” interface envisaged in TS 23.203 relates to pure 3GPP roaming situations wherein two PDPs in the mobile domain (i.e., two PCRFs) intervene in a data communication of a (roaming) UE—one PCRF residing in the home 3GPP domain (the so-called Home-PCRF or H-PCRF) (not shown), and the other one residing in the visited 3GPP domain (the so-called Visited-PCRF or V-PCRF) (not shown). In other words, the BPCF-PCRF relation by S9a (in the FMC architecture 10 in FIG. 1) may be considered to be conceptually similar to the relation between the V-PCRF and the H-PCRF via S9 in pure 3GPP roaming scenarios.
The foregoing described initiatives by 3GPP to offer FMC solutions. However, it is noted that BBF is also working at the same time on the requirements regarding what the support of 3GPP BBAI BB1 implies in the fixed network. The BroadBand Forum Working Text (WT)-203, revision 9 (August 2011), titled “Interworking between Next Generation Fixed and 3GPP Wireless Access” (hereafter “WT-203”), documents BBF's efforts to accommodate 3GPP interworking initiatives in the fixed domain. In the present discussion, portions of WT-203 related to policy and QoS interworking are incorporated by reference in their entireties. It is observed, however, that both 3GPP BBAI BB1 and BBF WT-203 assume exclusively an interworking scenario—i.e., two separated networks (fixed and mobile), with separated Authentication Authorization and Accounting (AAA) servers, gateways and policy managers. Only the interconnection mechanisms (like the “S9a” and “STa” reference points shown in FIG. 1) are defined, and no further convergence is proposed. Rather, convergence is a topic for 3GPP BBAI BB3, the scope of which is not yet commonly agreed by the industry.
A brief description of how policy framework is currently implemented in a broadband fixed network domain is now provided with reference to the fixed network domain 14 shown in FIG. 1. It is observed initially that Fixed Access Service Providers have very big and highly customized network deployments, with a policy framework commonly using a Remote Authentication Dial-In User Server/Service (RADIUS) protocol based infrastructure. In summary, there are two RADIUS-based mechanisms for implementing the policy framework in fixed access networks: (1) Proxy mode: In this mode, at IP session establishment, and when the BNG 34 sends the RADIUS Accounting Start towards the BBF AAA server 32, the AAA server 32 may forward such message towards the Policy Manager or BPCF 36. The BPCF 36 acknowledges the reception of such RADIUS Accounting message to the AAA 32, and the AAA 32 sends the acknowledge message towards the BNG 34. (2) Sidecar mode: In this mode, at IP session establishment, the BNG 34 sends the RADIUS Accounting Start towards both the AAA server 32 and the Policy Manager or BPCF 36. The BPCF 36 acknowledges the reception of such RADIUS Accounting Start message to the BNG 34.
Once the BPCF 36 gets the RADIUS Accounting Start message (whether in proxy mode or sidecar mode), it can make the policy decisions and may request the enforcement of the applicable policies. For such purpose, the BPCF 36 sends a RADIUS Change Of Authorization (COA) message towards the BNG 34 including the applicable policies.
Thus, from the above description of the proxy and sidecar modes and BPCF's response through a RADIUS COA message, it is seen that, in the fixed domain 14, the BNG 34 receives policies under a “push” model, i.e., in an unsolicited way, because there is no previous policy request—direct or indirect—from the BNG towards the Policy Manager or BPCF. (The RADIUS Accounting Start message is not in fact a policy request; it is just the sending of accounting data to be used for charging purposes). In contrast, the 3GPP PCC architecture for a 3GPP-EPC network in the mobile domain 12 is based on a “pull” model at IP Connectivity Access Network (IP-CAN) session establishment/modification, wherein a Gateway (GW) or Policy and Charging Enforcement Function (PCEF) (such as, for example, the PDN-Gw 18 in FIG. 1) receives policies to be enforced from a policy manager/PDP (e.g., the PCRF 22 in FIG. 1) upon request from the GW/PCEF. (See, for example, 3GPP TS 23.203, FIG. 7.2-1: interaction in flows 3 and 10 between the illustrated Gateway (GW) (which can be a PDN-Gw) and the policy manager PCRF). As mentioned before, instead of a PCEF as a PEP, a BBERF may function as a PEP as well.